Injection-molded refrigerator liner with air ducts

ABSTRACT

An injection-molded door liner for a door of a refrigerator appliance is provided. The door liner is injection molded as a single, integral piece and defines an icebox compartment, a cooling air inlet duct, and a cooling air outlet duct. A sealed cooling system circulates cooling air into the icebox compartment through the cooling air inlet duct and the cooling air is returned to the sealed cooling system through the cooling air outlet duct.

FIELD OF THE INVENTION

The present subject matter relates generally to appliances, such as refrigerator appliances, and liners for the same.

BACKGROUND OF THE INVENTION

Certain refrigerator appliances utilize sealed systems for cooling chilled chambers of the refrigerator appliances. A typical sealed system includes an evaporator and a fan, the fan generating a flow of air across the evaporator and cooling the flow of air. The cooled air is then provided through an opening into the chilled chamber to maintain the chilled chamber at a desired temperature. Air from the chilled chamber is circulated back through a return duct to be re-cooled by the sealed system during operation of the refrigerator appliance, maintaining the chilled chamber at the desired temperature.

In some refrigerator appliances, an ice maker may be mounted in a fresh food chamber. The ice maker may have a mold body configured to receive water that can freeze over time to form ice cubes. However, because the fresh food chamber is generally maintained at a temperature above the freezing point of water, the ice maker must be contained within a chilled chamber that is maintained at a freezer temperature. In order to achieve this, the ice maker is typically placed in a chilled chamber having an inlet and an outlet. A sealed system has a fan that circulates chilled air through the chamber by delivering the chilled air to the chilled chamber through the inlet and receiving the return air from the outlet.

A chilled chamber for housing an icemaker may be disposed in the refrigerator door of a bottom mount refrigerator. Such refrigerator doors commonly include an outer door frame, a door liner, and foam insulation. The outer door frame is typically constructed of rigid material such as steel and is stamped or otherwise formed to the desired door shape. The door liner is typically formed from a combination of injection-molded and thermoformed parts. The door liner is then sealed against the outer door frame to form an insulating cavity. Insulating foam is then sprayed inside the cavity to provide insulation and structural support for the door liner.

The inlet and outlet of the chilled chamber are typically formed by injection-molding or thermoforming a skeleton of the door liner and piercing holes for the inlet and outlet. To complete the formation of the inlet and outlet ducts, a separate thermoformed duct is formed and joined with the door liner. The additional parts require separate design, tooling, procurement, and storage. The joints are typically welded together or joined using tapes and adhesive. However, the holes and joints in the door liner create leak points that cause issues during the foam insulation process. Moreover, the holes may not have sufficient structural integrity, and may separate during the foam insulation process. Indeed, foam leaks around the air ducts of these assemblies are not uncommon, and frequently result in the scrapping of expensive foam door assemblies.

Accordingly, a refrigerator appliance including an injection-molded door liner that is integrally formed would be useful. More particularly, a door liner for a refrigerator appliance including an icebox defining an inlet and an outlet without requiring assembly of multiple parts would be especially beneficial.

BRIEF DESCRIPTION OF THE INVENTION

The present subject matter provides an injection-molded door liner for a refrigerator door and a method for forming such a door liner. More particularly, the door liner is injection molded as a single, integral piece and defines an icebox compartment, a cooling air inlet duct, and a cooling air outlet duct. A sealed cooling system circulates cooling air into the icebox compartment through the cooling air inlet duct and the cooling air is returned to the sealed cooling system through the cooling air outlet duct. The door liner simplifies assembly, reduces parts, and minimizes the likelihood of leaks. The door liner thereby reduces costs while increasing refrigerator performance and efficiency. Additional aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention.

In a first exemplary embodiment, an injection molded door liner for a door of a refrigerator appliance is provided. The door liner includes an icebox compartment defined at least in part by the door liner and having a back wall and a plurality of sidewalls. A cooling air inlet duct is defined by the door liner and is configured to receive cooling air from a sealed cooling system. A cooling air outlet duct is defined by the door liner and is configured to return cooling air to the sealed cooling system. The door liner is injection molded as a single, integral part.

According to another exemplary embodiment, a refrigerator appliance is provided. The refrigerator appliance includes a cabinet including a liner defining a chilled chamber and a door configured to provide access into the chilled chamber. A door liner is injection molded as a single, integral piece and is mounted in the door. The door liner defines a sub-compartment including an icebox cavity, an inlet for receiving chilled air into the icebox cavity from a sealed cooling system, and an outlet for returning chilled air to the sealed cooling system.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.

FIG. 1 provides a perspective view of a refrigerator appliance according to an exemplary embodiment of the present subject matter.

FIG. 2 provides a perspective view of the exemplary refrigerator appliance of FIG. 1 with refrigerator doors of the refrigerator appliance shown in an open position to reveal a fresh food chamber of the refrigerator appliance.

FIG. 3 provides an exploded perspective view of the refrigerator appliance door of FIG. 1 showing a door liner defining an icebox compartment.

FIG. 4 provides a schematic view of a sealed cooling system of the refrigerator appliance of FIG. 1.

FIG. 5 provides a perspective view of a door liner of the exemplary refrigerator appliance of FIG. 1.

FIG. 6 provides a rear view of the door liner of the exemplary refrigerator appliance of FIG. 1.

FIG. 7 provides a cross-sectional view of the cooling air inlet and outlet ducts defined in the door liner of the exemplary refrigerator appliance of FIG. 1 taken along Line 7-7 in FIG. 6.

FIG. 8 provides a close-up, perspective view of a cooling air inlet duct of the door liner of the exemplary refrigerator appliance of FIG. 1.

FIG. 9 provides a perspective view of a door liner of the exemplary refrigerator appliance of FIG. 1.

FIG. 10A provides a plot of a measured pressure drop of cooling air as it is circulated through the icebox compartment of the refrigerator appliance of FIG. 1 compared to the pressure drop in a prior design over various cooling air flow rates.

FIG. 10B provides a plot of a measured pressure drop of cooling air flowing across the inlet duct and the outlet duct of the icebox compartment of the refrigerator appliance of FIG. 1 compared to the pressure drop in a prior design over various cooling air flow rates.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

FIG. 1 provides a perspective view of a refrigerator appliance 100 according to an exemplary embodiment of the present subject matter. Refrigerator appliance 100 includes a cabinet or housing 120 that extends between a top 101 and a bottom 102 along a vertical direction V. Housing also extends along a lateral direction L and a transverse direction T, each of the vertical direction V, lateral direction L, and transverse direction T being mutually perpendicular to one another. Housing 120 defines chilled chambers for receipt of food items for storage. In particular, housing 120 defines fresh food chamber 122 positioned at or adjacent top 101 of housing 120 and a freezer chamber 124 arranged at or adjacent bottom 102 of housing 120. As such, refrigerator appliance 100 is generally referred to as a bottom mount refrigerator. It is recognized, however, that the benefits of the present disclosure apply to other types and styles of refrigerator appliances such as, e.g., a top mount refrigerator appliance or a side-by-side style refrigerator appliance. Consequently, the description set forth herein is for illustrative purposes only and is not intended to be limiting in any aspect to any particular refrigerator chamber configuration.

Refrigerator doors 128 are rotatably hinged to an edge of housing 120 for selectively accessing fresh food chamber 122. In addition, a freezer door 130 is arranged below refrigerator doors 128 for selectively accessing freezer chamber 124. Freezer door 130 is coupled to a freezer drawer (not shown) slidably mounted within freezer chamber 124. Refrigerator doors 128 and freezer door 130 are shown in the closed configuration in FIG. 1.

Refrigerator appliance 100 also includes a dispensing assembly 140 for dispensing liquid water and/or ice. Dispensing assembly 140 includes a dispenser 142 positioned on or mounted to an exterior portion of refrigerator appliance 100, e.g., on one of refrigerator doors 128. Dispenser 142 includes a discharging outlet 144 for accessing ice and liquid water. An actuating mechanism 146, shown as a paddle, is mounted below discharging outlet 144 for operating dispenser 142. In alternative exemplary embodiments, any suitable actuating mechanism may be used to operate dispenser 142. For example, dispenser 142 can include a sensor (such as an ultrasonic sensor) or a button rather than the paddle. A control panel 148 is provided for controlling the mode of operation. For example, control panel 148 includes a plurality of user inputs (not labeled), such as a water dispensing button and an ice-dispensing button, for selecting a desired mode of operation such as crushed or non-crushed ice.

Discharging outlet 144 and actuating mechanism 146 are an external part of dispenser 142 and are mounted in a dispenser recess 150. Dispenser recess 150 is positioned at a predetermined elevation convenient for a user to access ice or water and enabling the user to access ice without the need to bend-over and without the need to open refrigerator doors 128. In the exemplary embodiment, dispenser recess 150 is positioned at a level that approximates the chest level of a user. As described in more detail below, the dispensing assembly 140 may receive ice from an icemaker disposed in a sub-compartment of the fresh food chamber 122.

FIG. 2 provides a perspective view of a door of refrigerator appliance 100 shown with refrigerator doors 128 in the open position. Refrigerator appliance 100 includes a sub-compartment, e.g., icebox compartment 160 defined on refrigerator door 128. Icebox compartment 160 extends into fresh food chamber 122 when refrigerator door 128 is in the closed position. As discussed in greater detail below, an ice making assembly or icemaker 210 and an ice storage bin 208 (FIG. 3) may be positioned or disposed within icebox compartment 160. Thus, ice is supplied to dispenser recess 150 (FIG. 1) from the icemaker 210 and ice storage bin 208 in icebox compartment 160 on a back side of refrigerator door 128.

An access door 162 is hinged to refrigerator door 128 or to icebox compartment 160. Access door 162 permits selective access to icebox compartment 160. Any manner of suitable latch 164 is configured with icebox compartment 160 to maintain access door 162 in a closed position. As an example, latch 164 may be actuated by a consumer in order to open access door 162 for providing access into icebox compartment 160. Access door 162 can also assist with insulating icebox compartment 160, e.g., by thermally isolating or insulating icebox compartment 160 from fresh food chamber 122.

According to the illustrated embodiment, various storage components are mounted within fresh food chamber 122 to facilitate storage of food items therein as will be understood by those skilled in the art. In particular, the storage components include bins 166, drawers 168, and shelves 170 that are mounted within fresh food chamber 122. Bins 166, drawers 168, and shelves 170 are configured for receipt of food items (e.g., beverages and/or solid food items) and may assist with organizing such food items. As an example, drawers 168 can receive fresh food items (e.g., vegetables, fruits, and/or cheeses) and increase the useful life of such fresh food items.

As will be discussed below, refrigerator appliance 100 includes an icemaker 210 for producing ice within icebox compartment 160. In order to maintain icebox compartment 160 at a temperature below the freezing point of water, chilled air supply duct 180 and chilled air return duct 182 may be disposed on a side portion of the housing 120 of the refrigerator appliance 100. In this manner, the supply duct 180 and return duct 182 may recirculate chilled air from a sealed cooling system 250 through icebox compartment 160.

FIG. 3 shows an exploded perspective view of the refrigerator door 128. As explained above, refrigerator door 128 is an outer door movable between a closed position (FIG. 1) closing fresh food chamber 122 and an opened position allowing access to the interior of fresh food chamber 122 (FIG. 2). Refrigerator door 128 may have an outer panel 202 and an injection-molded door liner 204 attached to an inside of outer panel 202. Insulation (not shown), such as expandable foam can be present between outer panel 202 and door liner 204 in order to assist with insulating fresh food chamber 122 and icebox compartment 160. For example sprayed polyurethane foam may be injected into a cavity defined between outer panel 202 and door liner 204 after they are assembled.

Outer panels 202 and door liners 204 may be constructed of or with any suitable materials. Typically, outer panel 202 includes a main body formed of a structurally firm metal material such as steel, stainless steel, painted steel, aluminum, or any other suitably rigid material. Outer panel 202 may also have multiple inner and outer layers (not shown) as is known to provide coloring, fingerprint and smudge avoidance, insulation adhesion, etc. Freezer door 130 may be constructed in a similar manner as refrigerator doors 128.

Door liner 204 may be constructed of or with a suitable plastic material. For example, door liner 204 may be injection-molded plastic such as HIPS (high impact polystyrene—injection molding grade) or ABS (injection molding grade), which is typically more rigid than that of a thermoformed liner. Door liner 204 may define icebox compartment 160, which is formed of injection molded plastic. Accordingly, icebox compartment 160 provides a rigid frame on which various elements can be mounted to refrigerator door 128.

Icebox compartment 160 includes an interior area 206 (FIG. 5) in which an ice storage bin 208 may be removably located. In addition, an icemaker 210 may be disposed within the icebox compartment 160 and may be configured for forming ice which may be stored in ice storage bin 208. Ice storage bin 208 and icemaker 210 may be readily attached to icebox compartment 160 using, for example, clips, fasteners, or other securing means. Icemaker 210 may include a mold body 212 for receipt of water for freezing. In particular, mold body can receive liquid water and such liquid can freeze therein and form ice cubes. Icemaker 210 can harvest such ice cubes and direct such ice cubes to the ice storage bin 208 positioned within icebox compartment 160. For example, a motor 214 for driving an auger 216 for assisting in moving ice cubes from ice storage bin 208 can also be mounted directly in icebox compartment 160. Ice cubes at the bottom of the ice storage bin 208 can enter an ice chute (not shown) and flow through refrigerator door 128 to discharging outlet 144 and flow into a container or cup, e.g., in the manner discussed above. Access door 162 may enclose the interior area 206 of icebox compartment 160 and any items therein.

Various elements can be attached directly to icebox compartment 160, as mentioned above. For example, at least one of an ice storage bin 208, an icemaker 210, and a motor 214 for driving an auger 216 can be located in and be attached to the icebox compartment 160. In addition, other suitable electrical, liquid, and mechanical attachments can be provided within icebox compartment 160 in any desirable combination or configuration. Notably, because icebox compartment 160 is made of rigid injection-molded plastic, a more secure attachment and resulting structure can be achieved than if the icebox compartment 160 were simply a thermoformed liner.

As will be understood by those skilled in the art, ambient air within fresh food chamber 122 is not maintained at a sufficiently low temperature to permit formation of ice by icemaker 210. Thus, icebox compartment 160 is isolated or insulated from fresh food chamber 122 and includes features for facilitating formation of ice by icemaker 210. For example, chilled air from a sealed cooling system 250 (described in detail below) of refrigerator appliance 100 may be directed into icebox compartment 160 in order to cool icemaker 210 and/or ice storage bin 208. In alternative exemplary embodiments, a temperature of air within icebox compartment 160 may correspond to a temperature of air within fresh food chamber 122, such that ice within ice storage bin 208 melts over time.

To facilitate formation of ice within icemaker 210, icebox compartment 160 includes a chilled air inlet duct 220 and a chilled air outlet duct 222. Chilled air inlet duct 220 and chilled air outlet duct 222 are vertically aligned with chilled air supply duct 180 and chilled air return duct 182, respectively, positioned on housing 120. Chilled air ducts 180, 182 are in fluid communication with freezer chamber 124 and can receive chilled air therefrom and direct chilled air into icebox compartment 160. Chilled air can assist within formation of ice by icemaker 210 and/or storage of ice within ice storage bin 208. As an example, chilled air inlet duct 220 can receive chilled air from freezer chamber 124 via chilled air supply duct 180. Because chilled air within freezer chamber 124 can have a sufficiently low temperature to permit formation of ice, chilled air therefrom can assist or permit icemaker 210 to produce ice despite being positioned adjacent fresh food chamber 122. To facilitate the flow of chilled air from freezer chamber 124 to icemaker 210, chilled air outlet duct 222 can direct air within icebox compartment 160 away from icemaker 210, e.g., back to freezer chamber 124 via chilled air return duct 182.

Access door 162 can be used to maintain interior area 206 at a temperature lower than that of fresh food chamber 122, for example below freezing. Access door 162 can be hinged to door liner 104, or may simply be removable from door liner 104. By defining chilled air inlet and outlet ducts 220, 222 to cool interior area 206, icebox 160 need not be separately cooled, although a fan or other device may be employed to move cooled air from freezer chamber 124 into the interior area 206. An ice dispenser outlet (not shown) is provided to feed ice cubes from interior area 206 and ice storage bin 208 through as passageway in outer panel 202 and door liner 204 and through to dispenser 142.

As is known in the art, a heating element 228 may be provided in icebox compartment 160 to prevent or reduce undesired condensation in view of the fact that icebox compartment 160 may be located within refrigerator door 128 of fresh food chamber 122, which is at a different temperature than the sub-freezing temperature inside icebox compartment 160. Heating element 228 also prevents undesired freezing of any condensation that might form at such location, which may clog the icemaker 210 or might possibly make it more difficult to open access door 162. Heating element 228 may be a strip resistance heater located in icebox compartment 160, and may be, for example attached to door liner 204.

As shown, icebox compartment 160 is defined by door liner 204 of refrigerator door 128. However, one skilled in the art will appreciate that icebox compartment 160 may be located on any surface of housing 120. For example, it could just as easily be located on freezer door 130 of freezer chamber 124 or configured according to other appliance/door designs. In addition, embodiments of the present subject matter may be employed to construct door liners for components other than icebox compartment 160. For example, the technologies described herein may be used to construct integral cabinets, shelving, and other features for refrigerator appliance 100.

FIG. 4 provides a schematic view of certain components of refrigerator appliance 100. As may be seen in FIG. 4, refrigerator appliance 100 includes a sealed cooling system 250 for executing a vapor compression cycle for cooling air within refrigerator appliance 100, e.g., within fresh food chamber 122 and freezer chamber 124. Sealed cooling system 250 includes a compressor 252, a condenser 254, an expansion device 256, and an evaporator 258 connected in series and charged with a refrigerant. As will be understood by those skilled in the art, sealed cooling system 250 may include additional components, e.g., at least one additional evaporator, compressor, expansion device, and/or condenser. As an example, sealed cooling system 250 may include two evaporators.

Within sealed cooling system 250, gaseous refrigerant flows into compressor 252, which operates to increase the pressure of the refrigerant. This compression of the refrigerant raises its temperature, which is lowered by passing the gaseous refrigerant through condenser 254. Within condenser 254, heat exchange with ambient air takes place so as to cool the refrigerant and cause the refrigerant to condense to a liquid state.

Expansion device (e.g., a valve, capillary tube, or other restriction device) 256 receives liquid refrigerant from condenser 254. From expansion device 256, the liquid refrigerant enters evaporator 258. Upon exiting expansion device 256 and entering evaporator 258, the liquid refrigerant drops in pressure and vaporizes. Due to the pressure drop and phase change of the refrigerant, evaporator 258 is cool relative to fresh food and freezer chambers 122 and 124 of refrigerator appliance 100. As such, cooled air is produced and refrigerates fresh food and freezer chambers 122 and 124 of refrigerator appliance 100. Thus, evaporator 258 is a type of heat exchanger which transfers heat from air passing over evaporator 258 to refrigerant flowing through evaporator 258.

Refrigerator appliance 100 further includes a valve 260 for regulating a flow of liquid water to icemaker 210, e.g., into a mold body of icemaker 210. Valve 260 is selectively adjustable between an open configuration and a closed configuration. In the open configuration, valve 260 permits a flow of liquid water to icemaker 210. Conversely, in the closed configuration, valve 260 hinders the flow of liquid water to icemaker 210.

Refrigerator appliance 100 also includes an air handler 262. Air handler 262 is configured for urging a flow of chilled air from freezer chamber 124 into icebox compartment 160, e.g., via supply and return ducts 180, 182 and chilled air ducts 220, 222, as discussed above. Air handler 262 can be positioned within supply and return ducts 180, 182 of sealed cooling system 250 and be any suitable device for moving air. For example, air handler 262 can be an axial fan or a centrifugal fan.

Refrigerator appliance 100 further includes a controller 264. Operation of the refrigerator appliance 100 is regulated by controller 264 that is operatively coupled to control panel 148. In one exemplary embodiment, control panel 148 may represent a general purpose I/O (“GPIO”) device or functional block. In another exemplary embodiment, control panel 148 may include input components, such as one or more of a variety of electrical, mechanical or electro-mechanical input devices including rotary dials, push buttons, touch pads, and touch screens. Control panel 148 may be in communication with controller 264 via one or more signal lines or shared communication busses. Control panel 148 provides selections for user manipulation of the operation of refrigerator appliance 100. In response to user manipulation of the control panel 148, controller 264 operates various components of refrigerator appliance 100. For example, controller 264 is operatively coupled or in communication with compressor 252, valve 260, and air handler 262, such that controller 264 can operate such components. Controller 264 may also be in communication with a variety of sensors, such as, for example, a temperature sensor 266. Controller 264 may receive signals from temperature sensor 266 that correspond to a temperature of an atmosphere or air within, e.g., icebox compartment 160.

Controller 264 includes memory and one or more processing devices such as microprocessors, CPUs or the like, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with operation of refrigerator appliance 100. The memory can represent random access memory such as DRAM, or read only memory such as ROM or FLASH. The processor executes programming instructions stored in the memory. The memory can be a separate component from the processor or can be included onboard within the processor. Alternatively, controller 264 may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software.

Referring now to FIG. 5, a perspective view of door liner 204 of exemplary refrigerator appliance 100. According to the illustrated exemplary embodiment, door liner 204 is injection molded as a single, integral part and configured to be mounted on refrigerator door 128 of refrigerator appliance 100. Door liner 204 may define a lower compartment 280 which may receive, for example, a variety of mechanical components used for operating the dispensing assembly 140. For example, lower compartment 280 of door liner 204 may receive a water tank, one or more valves, or other mechanical components. In such an embodiment, a separate cover (not shown) is typically placed over lower compartment 280 to conceal the mechanical components. Additionally, or alternatively, lower compartment 280 may receive a door storage bin (not shown) or may be used in any other suitable manner.

The door liner 204 may also define an upper compartment, e.g., icebox compartment 160. As shown in the illustrated embodiment, icebox compartment 160 is defined by a plurality of walls. More particularly, icebox compartment 160 generally includes a rear wall 282, a first sidewall 284, a laterally opposite second sidewall 286, a top wall 288, and a bottom wall 290. As described above, access door 162 (FIG. 2) can be used to provide selective access to icebox compartment 160.

As explained above, refrigerator appliance 100 includes a sealed cooling system 250 for delivering chilled air to icebox compartment 160 defined by door liner 204. More particularly, icebox compartment 160 defines an inlet—e.g., cooling air inlet duct 220—which is defined by door liner 204 and may be configured to receive cooling air from the sealed cooling system 250 via supply duct 180. Similarly, icebox compartment 160 defines an outlet—e.g., cooling air outlet duct 222—which is defined by door liner 204 and may be configured to return cooling air from the sealed cooling system 250 via return duct 182. For the embodiment depicted, cooling air inlet duct 220 is defined in first sidewall 284 of door liner 204 proximate to the top wall 288 and cooling air outlet duct 222 is defined in first sidewall 284 of liner 204 proximate to the bottom wall 290.

As described above, refrigerator appliance 100 includes air handler 262 to provide a flow of cooling air from sealed cooling system 250 to icebox compartment 160. More specifically, chilled air travels from supply duct 180 in cabinet 120, through cooling air inlet duct 220, and into icebox compartment 160. The chilled air lowers the temperature in icebox compartment 160 before passing through return duct 182 and back to the sealed cooling system 250 through chilled air outlet duct 222. In this manner, the sealed cooling system 250 distributes chilled air throughout the icebox compartment 160 to maintain the temperature at freezer temperature so that ice may be formed.

Referring now to FIGS. 6 and 7, inlet duct 220 and outlet duct 222 will be described in more detail. Although the inlet duct 220 is used here for the purposes of description, the outlet duct 222 may be similarly formed according to an exemplary embodiment. The inlet duct 220 may extend from a first end 292 proximate to one of the plurality of sidewalls of the icebox compartment—e.g., first sidewall 284—to a second end 294 proximate to a door mating surface 296 defined by door liner 204. As shown in the illustrated embodiment, the inlet duct 220 extends in a substantially orthogonal direction from first sidewall 284. However, inlet duct 220 may alternatively extend from first sidewall 284 in a different direction and/or from a different wall of icebox compartment 160. Notably, as shown in the illustrated embodiment of FIGS. 6 and 7, door liner 204 defines a space 298 around each of the inlet duct 220 and the outlet duct 222, such that the inlet duct 220 and the outlet duct 222 may be surrounded in insulating foam (not shown).

Referring now to FIGS. 8 and 9, it can be seen that the second end 294 of inlet duct 220 is disposed at the door mating surface 296. As shown, the injection molded door liner 204 may define inlet duct 220 and outlet duct 222 such that they each comprise a rectangular profile having radiused corners. Alternatively, inlet duct 220 and outlet duct 222 may each comprise an oblong profile, or any other suitable profile for enhancing cooling airflow and system performance. In addition, by virtue of the injection molding process, the transitions, corners, or edges defining the profile of inlet duct 220 and outlet duct 222 may be molded to have a smooth profile, to have small or large radiused corners, or to have another flow enhancing profile, as desired.

For example, the second end 294 of the inlet duct 220 may be configured to receive a duct gasket 310 (FIG. 9). In this regard, injection molded door liner 204 may define a profile that is configured to securely accept door gasket 310. Alternatively, according to another exemplary embodiment, door liner 204 may be configured to receive a duct bracket (not shown) which is configured to receive the duct gasket 310. As shown, duct gasket 310 protrudes from door mating surface 296 of door liner 204 and is typically made from a resilient material, e.g., rubber. In this manner, duct gasket 310 may be compressed to form a seal with supply duct 180 when refrigerator door 128 is in the closed position. Similarly, outlet duct 222 may be configured to receive duct gasket 310, which is compressed to form a seal with return duct 182 when refrigerator door 128 is in a closed position. According to another embodiment, duct gasket 310 may be disposed on housing 120 of refrigerator appliance 100. In this regard, duct gasket 310 surrounds supply duct 180 and return duct 182. For this embodiment, door mating surface 296 of door liner 204 may define a profile for receiving the duct gasket 310 and providing a seal between, for example, supply duct 180 and inlet duct 220.

Although the exemplary embodiments described above refer to an integral, injection-molded door liner 204 mounted onto refrigerator door 128 and defining an icebox compartment 160, one skilled in the art will appreciate that aspects of the present subject matter may be used to create liners for different applications. For example, a door liner may be used in different chambers of refrigerator appliance 100, and may serve purposes other than defining icebox compartment 160. Exemplary door liners may even be used on other consumer appliances. Indeed, features of the present invention may be used in any application where it is desirable to have an injection-molded part having integral inlet and outlet ports or ducts.

Now that the construction of refrigerator door 128 and door liner 204 according to an exemplary embodiment has been presented, a method of forming these parts will now be described. Such a method may include fabricating door liner 204 as a unitary liner, e.g., such that door liner 204 is integrally formed of a single continuous piece of plastic, metal or other suitable material. The outer panel 202 of refrigerator is typically cut or stamped and formed from a structurally firm metal material such as steel, stainless steel, painted steel aluminum, or any other suitably rigid material. Door liner 204 is injection molded as a single, integral piece, and defines icebox compartment 160, cooling air inlet duct 220, and cooling air outlet duct 222. Door liner 204 is mounted to the outer panel 202 to form refrigerator door 128 having a hollow cavity. The cavity is then filled with insulating foam.

Integral formation of the entire door liner 204 requires mold tooling specifically designed to form icebox compartment 160, as well as inlet and outlet ducts 220, 222. Once the mold pieces are in place, the mold is injected with injection-molding grade plastic to form a single-piece door liner. After the injected plastic is solidified, the mold parts are removed to reveal a single-piece door liner having integral cooling ducts.

By contrast, prior methods of forming a refrigerator door liner have required multiple parts and a complicated assembly process. More specifically, an icebox frame would be separately formed by injection molding or another process. Holes would be formed in the icebox frame to define the first end of each duct. A perimeter liner would be separately formed and have holes punched for defining the opposite, second end of each duct. The icebox frame and the perimeter liner would then be joined together by, e.g., friction welding, or by using tape or adhesive. Finally, a duct portion would be separately formed, and the duct portion would be inserted between the holes in the icebox frame and perimeter liner, and then joined in a manner similar to the icebox frame and perimeter liner. In addition to the manufacturing process being significantly more difficult and time-consuming, the resulting door liners frequently have small leaks through which foam might leak during the foam insulation process. Notably, using the above-described method of forming an integral door liner by injection molding, manufacturing costs may be reduced and the performance of the resulting door liner may be improved, as discussed below.

Door liner 204 formed according to the above-described method or exemplary embodiments may exhibit significant performance advantages over prior, multi-part liners. From a manufacturing perspective, fewer parts are required to be procured, stored, and assembled. Additionally, assembly is simplified as parts do not need to be joined, taped, sealed, or otherwise assembled. Finally, there are fewer potential leak points where insulating foam might escape during the insulation process. From a performance perspective, because the door liner is produced as one part, as opposed to several parts, the tolerances of the finished door liner assembly can be held tighter, thus contributing to a more robust liner. Furthermore, more design options may be available for the refrigerator appliance due to the more precise part features. For example, the method may permit formation of an icebox defining integral inlet and outlet ports that may be designed for optimal performance. Moreover, the inlet and outlet may be enhanced and exhibit a smooth profile such that frictional losses may be minimized and airflow performance may be optimized.

Door liners constructed in accordance with the above-described example embodiments have demonstrated improved performance compared to prior designs. For example, FIG. 10A provides a plot of a measured pressure drop of cooling air as it is circulated through icebox compartment 160 at various flow rates compared to the pressure drop in a prior design. To determine the system pressure drop, the difference between air pressures at two points in the sealed cooling system 250 is determined. The first pressure may be measured, for example, at the air handler 262 outlet, and the second pressure may be measured, for example, at the air handler 262 inlet. As may be seen in FIG. 10A, the pressure drop experienced by the sealed cooling system 250 is larger for prior designs. Similarly, FIG. 10B provides a plot of a measured pressure drop of cooling air flowing across inlet duct 220 and outlet duct 222 of icebox compartment 160 compared to the pressure drop in a prior multi-part assembly design. As may be seen in FIG. 10B, the pressure drop across inlet duct 220 and outlet duct 222 is significantly lower for injection molded door liner 204, especially at higher flow rates. A lower pressure drop means friction losses within the sealed cooling system 250 are decreased, more cooling air is received in icebox compartment 160, and the performance and efficiency of the refrigerator appliance 100 is improved.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 

What is claimed is:
 1. An injection molded door liner for a door of a refrigerator appliance, the door liner comprising: an icebox compartment defined at least in part by the door liner, the icebox compartment having a back wall and a plurality of sidewalls; a cooling air inlet duct defined by the door liner and configured to receive cooling air from a sealed cooling system; and a cooling air outlet duct defined by the door liner and configured to return cooling air to the sealed cooling system, wherein the door liner is injection molded as a single, integral part.
 2. The injection molded door liner of claim 1, wherein the door liner defines a space around each of the inlet duct and the outlet duct, such that the inlet duct and the outlet duct may be surrounded in insulating foam.
 3. The injection molded door liner of claim 1, wherein the cooling air inlet duct and the cooling air outlet duct extend from a first end proximate to one of the plurality of sidewalls of the icebox compartment to a second end proximate to a door mating surface defined by the door liner.
 4. The injection molded door liner of claim 3, wherein the second end of the inlet duct is configured to receive an inlet duct gasket and the second end of the outlet duct is configured to receive an outlet duct gasket.
 5. The injection molded door liner of claim 4, wherein the inlet duct gasket is compressed to form a seal with a cooling air supply duct and the outlet duct gasket is compressed to form a seal with a cooling air return duct when the door is in a closed position.
 6. The injection molded door liner of claim 1, wherein the door liner is between about 1/16 inch and 3/16 inch thick.
 7. The injection molded door liner of claim 1, wherein the door liner is about ⅛ inch thick.
 8. The injection molded door liner of claim 1, wherein the inlet duct and the outlet duct each comprise a rectangular profile having radiused corners.
 9. The injection molded door liner of claim 1, wherein the inlet duct and the outlet duct each comprise an oblong profile.
 10. The injection molded door liner of claim 1, wherein the door liner is disposed in a fresh food chamber and the icebox compartment comprises an ice maker and an ice storage bin.
 11. A refrigerator appliance, comprising: a cabinet including a liner defining a chilled chamber; a door configured to provide access into the chilled chamber; a door liner that is injection molded as a single, integral piece and mounted in the door, the door liner defining a sub-compartment, the sub-compartment comprising: an icebox cavity; an inlet for receiving chilled air into the icebox cavity from a sealed cooling system; and an outlet for returning chilled air to the sealed cooling system.
 12. The refrigerator appliance of claim 11, wherein the door liner defines a space around each of the inlet and the outlet, such that the inlet and the outlet may be surrounded in insulating foam.
 13. The refrigerator appliance of claim 11, wherein the inlet and the outlet extend from a first end proximate to the icebox cavity to a second end proximate to a door mating surface defined by the door liner.
 14. The refrigerator appliance of claim 13, wherein the second end of the inlet is configured to receive an inlet gasket and the second end of the outlet is configured to receive an outlet gasket.
 15. The refrigerator appliance of claim 14, wherein the inlet gasket is compressed to form a seal with a chilled air supply duct and the outlet gasket is compressed to form a seal with a chilled air return duct when the door is in a closed position.
 16. The refrigerator appliance of claim 11, wherein the door liner is between about 1/16 inch and 3/16 inch thick.
 17. The refrigerator appliance of claim 11, wherein the door liner is about ⅛ inch thick.
 18. The refrigerator appliance of claim 11, wherein the inlet and the outlet each comprise a rectangular profile having radiused corners.
 19. The refrigerator appliance of claim 11, wherein the inlet and the outlet each comprise an oblong profile.
 20. The refrigerator appliance of claim 11, wherein the icebox cavity comprises an ice maker and an ice storage bin. 